A method for manufacturing a low-temperature polycrystalline silicon thin film is a new generation method of a thin film transistor liquid crystal display, which is an a-Si film changed to a polysilicon thin film layer through aLaser annealing process. The polysilicon thin film layer is used to form thin film transistors of data lines and scan lines in the liquid crystal display panel. The moving velocity of electrons of polysilicon thin film transistors is one hundred times faster than amorphous silicon elements. Therefore, rapid response of the liquid crystal display panel, highlight display, and high resolution can be implemented.
Refer to FIGS. 1A to 1F, which are schematic views of a traditional method for manufacturing the thin film transistor.
Refer to FIG. 1A, a first photoresist pattern 101 is formed on a semiconductor substrate 102. The the semiconductor substrate 102 implements a first ion implantation through using the first photoresist pattern as a mask. Refer to FIG. 1B, an area uncovered by the first photoresist pattern 101 forms a preparation source 104 and a preparation drain 103.
Refer to FIG. 1C, the first photoresist pattern 101 is removed, and a gate insulating layer 105 and a gate metal layer 106 are sequentially deposited on the semiconductor substrate 102, and a second photoresist pattern 107 is formed on the gate metal layer 106.
Refer to FIG. 1D, the gate metal layer 106 is etched. Specifically, the gate metal layer 106 uncovered by the first photoresist pattern 101 is etched. As the etching time passes, a side wall of the gate metal layer 106 is etched gradually to form a new gate metal layer 106a, and then the second photoresist pattern 107 is removed in FIG. 1E.
Refer to FIG. 1F, a source and a drain are formed by implementing a second ion implantation, wherein the source and the drain include a heavily doped drain region 103, 104 and a lightly doped drain region 109, 108.
As described above in the method for manufacturing a thin film transistor, the lightly doped drain region is formed by forming two photoresist patterns, which is a complicated process, and has long production cycle, and is not good for production. As a result, it is necessary to provide method for manufacturing a thin film transistor, which is a simple process, and has a small negative effect for the uniformity of ion implantation, so that the electron mobility of the heavily doped drain region and the lightly doped drain region can be enhanced.